Check out the new @mentions and Tagging Feature!
We're testing a feature out on the forums, user @mentions (Twitter style). You can also tag users on a post/thread at the top of each page.Please have a play and PM Simon or post here if you experience any issues.

I ended up building to a new folder and it started working. The only thing I can think is the first time I did a build I didn't have the Multiple Touch extension, so subsequent builds to that folder...